It also allows you to own multiple copies of the same game, which is another huge step in regards to parental controls. If you and both of your kids enjoy a game, you can buy three copies for your account and set restrictions on when/how long they can use it.
I don’t think it does. It allows 3 members to play if there are 3 copies in the family, but each account can still only have 1 copy. You can’t buy 3 copies for your account.